Clocking architecture in stacked and bonded dice

ABSTRACT

A method and apparatus for distributing clock signals throughout an integrated circuit is provided. An embodiment comprises a distribution die which contains either the clock signal distribution network by itself, or the clock signal distribution network in tandem with a clock signal generator. The distribution die is electrically connected through an interface technology, such as microbumps, to route the clock signals to the functional circuits on a separate functional die. Alternatively, the distribution die could be electrically connected to more than one die at a time, using vias through the distribution die to route the clock signals to the different die. This separate distribution die reduces the coupling between lines and also helps to prevent signal skew as the signal moves through the distribution network.

TECHNICAL FIELD

The present invention relates generally to a system of semiconductordevices and, more particularly, to a system and method for distributingclock signals through a semiconductor device.

BACKGROUND

In order for an integrated circuit to operate properly, some elementswithin the integrated circuit must be synchronized. One common method ofsynchronizing elements of an integrated circuit is to use a clock signalthat is routed to the elements. This clock signal is generated using aclock signal generator and then distributed to the various elementsthrough a clock signal distribution network.

The physical clock signal distribution network is made up of conductivelines formed on the integrated circuit and interweaved among thefunctional blocks and the power grid. As such, the physical design of aclock signal distribution network is heavily dependent upon theplacement and other features located on the die.

However, this physical distribution network has some serious drawbacks.The first such drawback is timing skew. This occurs when clocking signaldelays to different parts of the integrated circuit are not equal,thereby causing the various elements to be out of synch. Timing skew canbe caused by electromagnetic propagation delays, buffer delays in thedistribution network, and resistive-capacitive delays associated withthe distribution lines themselves. This problem is further exacerbatedby the routing constraints of placing the lines between, around, andamong the other functional elements of the integrated circuit.

Another problem is corruption of the clock signal due to coupling fromthe signal network and/or the power network. When the clock distributionnetwork is integrated among the power nets and even among themselves,the signals within each line will interfere with the signals in theother lines, and cause some corruption of the clock signal. Such aproblem is normally solved by increasing the distance between thecoupling lines, but, in a single, closely packed integrated circuit,this solution is not feasible because it incurs prohibitive areapenalty.

Yet another problem involves a simple matter of efficiency. Because ofthe placement of the clocks and signals, the clock distribution networkmust be routed around the functional elements and power networks of therest of the die. This design is simply inefficient because thedistribution network can rarely be run in a straight line between theclock signal generator and the element to be controlled.

Accordingly, what is needed is a clock distribution network that isdesigned to improve clock purity and prevent skew problems across a diewhile improving die area utilization in clocked integrated circuits.

SUMMARY OF THE INVENTION

These and other problems are generally solved or circumvented, andtechnical advantages are generally achieved, by preferred embodiments ofthe present invention which form the clock signal distribution networkon a separate distribution die that is electrically coupled to afunctional die.

In accordance with an embodiment of the present invention, asemiconductor device comprises a first functional die with functionalcircuitry formed therein and a distribution die with a clock signaldistribution network formed therein. The outputs of the clock signaldistribution network are connected to the functional circuitry.

In accordance with another embodiment of the present invention, asemiconductor device comprises a distribution die with a clock signalgenerator connected to a clock signal distribution network. The outputsof the clock signal distribution network are connected to functionalcircuitry located on a separate functional die.

In accordance with yet another embodiment of the present invention, asystem for distribution clock signals to multiple functional diescomprises a distribution die that comprises a clock distributionnetwork. The clock distribution network is connected to at least twofunctional die.

In accordance with yet another embodiment of the present invention, asystem for multiple clock distribution networks on multiples dies to asingle functional die. The clock distribution network is distributed onat least two clock dies.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawing, in which:

FIGS. 1 a-1 b illustrate system level block diagrams of embodiments ofthe present invention;

FIG. 2 illustrates a circuit diagram of a clock signal generator inaccordance with an embodiment of the present invention;

FIG. 3 illustrates a block diagram of a phased-lock loop in accordancewith an embodiment of the present invention;

FIG. 4 illustrates a clock distribution network in accordance with anembodiment of the present invention;

FIG. 5 illustrates a distribution die bonded to a functional die inaccordance with an embodiment of the present invention;

FIGS. 6 a-6 c illustrate different configurations of a singledistribution die bonded to a first functional die and a secondfunctional die in accordance with an embodiment of the presentinvention; and

FIGS. 7 a-7 b illustrate different configurations of a single functionaldie bonded to a first distribution die and a second distribution die inaccordance with an embodiment of the present invention.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the presently preferred embodiments arediscussed in detail below. It should be appreciated, however, that thepresent invention provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

The present invention will be described with respect to embodiments in aspecific context, namely a clock signal generation and distributionsystem. The invention may also be applied, however, to otherdistribution networks.

With reference now to FIG. 1 a, there is shown a system level blockdiagram in accordance with of an embodiment of the present invention. Inthis diagram there is one functional die 103 that contains circuitry fora clock signal generator 107 and other functional circuitry 109 a-109 n.The functional circuitry 109 a-109 n may be, for example, logiccircuits, memory circuits, any type of circuitry that requires a clocksignal, or the like. Further, the number of functional circuits 109a-109 n is dependent upon the design of the functional die 103, and isnot meant to be limited to the number of functional circuits 109 a-109 nshown in FIG. 1 a.

In the embodiment of the present invention illustrated in FIG. 1 a, itshould be noted that the functional circuits 109 a-109 n may beinterconnected. A passive distribution die 101 that contains thephysical aspects of a clock signal distribution network 105 iselectrically coupled to the functional die 103. Generally, the passivedistribution die 101 routes signals, such as clock signals, generatedfrom off of the distribution die 101 and does not generate the clocksignal on the distribution die 101 itself. The input to the clock signaldistribution network 105 is connected to the clock signal generator 107and the outputs from the clock signal distribution network 105 areelectrically connected to the various functional circuits 109 a-109 nlocated on the functional die 103.

FIG. 1 b illustrates another embodiment of the present invention, inwhich the distribution die 101 is an active distribution die. In thisembodiment, the clock signal generator 107 is not located on thefunctional die 103, but is, instead, located on the distribution die 101itself. Accordingly, the clock signal is generated on the distributiondie 101 and then input into the clock signal distribution network 105.The outputs of the clock signal distribution network 105 areelectrically connected to the various functional circuits 109 a-109 nsimilarly to the first embodiment of the present invention. This wouldallow for a cleaner overall signal, because the coupling between theclock signal distribution network 105 (on the distribution die 101) andthe power and signal networks of the functional die 103 will be reduced.

It should be noted that FIGS. 1 a and 1 b illustrate embodiments inwhich there is a single clock signal generator 107. One of ordinaryskill in the art will appreciate, however, that multiple clock signalgenerators 107 may be located on the distribution die 101, thefunctional die 103, both or on a complete separate die altogether.Embodiments of the present invention may be utilized with any of theseconfigurations.

FIG. 2 illustrates a clock signal generator 107 that may be used in anembodiment of the present invention. In an embodiment, this clock signalgenerator 107 comprises a quartz crystal 201 that produces anoscillating signal when power is applied. The crystal 201 has a firstterminal that is connected to a first node 203 and a second terminalthat is connected to a second node 205. The first node 203 and thesecond node 205 are electrically connected to a first capacitor 209 anda second capacitor 211, respectively, that are each connected to ground.The first node 203 and the second node 205 are connected to each otherthrough a resistor 207.

This clock signal generator 107 additionally has a first inverter 213, asecond inverter 215, a third inverter 217, and a fourth inverter 218.Each of the inverters is composed of a PMOS pull-up transistor 219coupled in series to an NMOS pull-down transistor 221. The sources ofthe pull-up transistors 219 are connected to a voltage supply V_(cc) andthe drains of the pull-up transistors 219 are connected to the sourcesof the pull-down transistors 221 and to the output of the inverters.

The gates of the first inverter 213 are connected to the first node 203,and the output of the first inverter 213 is connected to the gates ofthe second inverter 215. The output of the second inverter 215 isconnected to both the gates of the third inverter 217 as well as to thegates of the fourth inverter 218. The output of the third inverter 217is connected to the second node 205. Finally, the output of the fourthinverter 218 is the external clock signal ECLK to be generated.

As stated above with reference to FIGS. 1 a-1 b, the clock signalgenerator 107 can be manufactured on either the distribution die to forman active distribution die (FIG. 1 b) or on the functional die (FIG. 1a), to form a passive distribution die. However, it is also contemplatedas part of this invention that the clock signal generator 107 could alsobe located on neither the functional die or the distribution die. Inthis case the clock signal generator 107 could be located on acompletely separate die or else be integrated into another die, whichwould be electrically connected to the clock signal distribution network105 on the distribution die 101.

FIG. 3 is a block diagram of a phase-locked loop 300 that may be used inaccordance with an embodiment of the present invention. In somesituations, particularly in embodiments utilizing a passive distributiondie 101 as illustrated in FIG. 1 b, it may be desirable to include asecond clock signal generator, such as the phase-locked loop 300, tolimit the skew that has already occurred from the clock signal generator107 to the die where the functional circuits 109 a-109 n are located.The phase-locked loop 300 may be formed on either the functional die 103or the distribution die 101. Generally, the phase-locked loop 300produces a new internal clock signal ICLK that is synchronized with theexternal clock signal ECLK.

In an embodiment the phase-locked loop 300 comprises phase detector 301,a charge pump 303, a loop filter 305, and a voltage-controlledoscillator (VCO) 307. The external clock signal ECLK enters thephase-locked loop 300 and is compared by the phase detector 301 to theinternal clock signal ICLK, part of which has been fed back from thevoltage-controlled oscillator 307. Based upon the differences betweenthe external clock signal ECLK and the internal clock signal ICLK, thephase detector 301 generates a pulse to the charge pump 303, whichoutputs an electric current according to this pulse. The loop filter 305attenuates the electric current from the charge pump 303 before itreaches the voltage-controlled oscillator 307.

The voltage-controlled oscillator 307 obtains the signal from the loopfilter 305 and generates an internal clock signal ICLK. A portion ofthis internal clock signal ICLK is looped back as a second input to thefrequency detector 301 for comparison to the external clock signal ECLK,and the remainder of the signal is sent to the clock distributionnetwork (as described below with reference to FIG. 4).

As one of ordinary skill in the art will realize, the phase-locked loop300 is described with reference to FIG. 3 above is merely one of manytypes of secondary clock signal generators that could be utilized withinthe scope of the present invention. The above description is meantmerely as an example, and is not intended to limit the present inventionto the embodiment described above. Other clock signal generators, suchas phase-locked loops with pulse shaping circuits, multiple phase clocksignal generators, differential clock signal generators, and the like,are equally intended to be within the scope of the present invention.

FIG. 4 illustrates the first few branches of a typical clock signaldistribution network 105 that can be used to transport the internalclock signal ICLK from the phase-locked loop 300 to the functionalcircuits 109 a-109 n of the functional die. In an embodiment, thetypical distribution network 105 shown in FIG. 4 comprises aninterconnected network of “branches” and buffers 401 arranged in a“tree” type of structure. In this layout the internal clock signal ICLKstarts in a single line from the phase-locked loop 300 and then“branches” into the other lines, continuing to “branch” until theinternal clock signal ICLK reaches each of the functional circuits 109a-109 n at approximately the same time.

However, as one skilled in the art will know, the “tree” architecture isnot the only architecture that can be used for the clock distributionnetwork 105. Other architectures, such as grid-based networks orcombinations of tree and grid-based networks, could alternatively beused, and are also intended to be included within the scope of thepresent invention. The above description is merely meant to beillustrative of one embodiment, and is not meant to limit the presentinvention to that embodiment.

Buffers 401 and an associated power network (not shown) may be locatedalong the lines of the distribution network 105 to help transport theinternal clock signal ICLK. In the simplest form, the buffers 401 areused as amplifiers to amplify the internal clock signals ICLK after theyhave been split among the various branches of the distribution network105. In an embodiment the buffers 401 are made of one or more invertersthat amplify the internal clock signal ICLK as it progresses through thedistribution network 105. However, it is also possible that a clockdistribution network may not need buffers 401 and be purely passive.

However, the buffer circuitry 401 could alternatively be modified invarious ways to help with synchronization problems. As an example thebuffers 401 could comprise comparators that compare one internal clocksignal ICLK to a complementary internal clock signal to ensure that theoutput of the buffers 401 is synchronized with other internal clocksignals ICLK in the distribution network 105. If necessary, the buffers401 could also be designed to intentionally delay the internal clocksignal ICLK in order to ensure synchronization between the functionalcircuits 109 a-109 n of the circuit. Any of these modified bufferdesigns are intended to be within the scope of the present invention,and the above description is not meant limit the present invention.

FIGS. 5, 6, and 7 illustrate different methods of bonding thedistribution die 101 to one or more functional dies in accordance withembodiments of the present invention. It should be noted, however, thatwhile FIGS. 5, 6, and 7 refer to one or more distribution dies 101, thedistribution die 101 may include either a passive distribution die 101as illustrated in FIG. 1 a or an active distribution die 101 asillustrated in FIG. 1 b.

Referring first to FIG. 5, the distribution die 101 may be bonded to asingle functional die 103 using microbump technology. For example, amicrobump tape (not shown) is provided with the microbumps 505 placed ina pattern corresponding to a first pattern of bond pads 507 on thedistribution die 101 and a second pattern of bond pads 509 on thefunctional die 103. The microbump tape is placed onto the distributiondie 101 with an insulating layer (not shown) between the distributiondie 101 and the tape, the insulating layer being patterned to allowelectrical connections to connect through the insulating layer. Thedistribution die 101 with the microbumps 505 is then placed onto thefunctional die 103 such that the microbumps 505 align with the secondpattern of bond pads 509 on the functional die 103 to form theelectrical connection.

However, one skilled in the art will recognize that any suitable bondingtechnology could be used to bond the distribution die 101 to thefunctional die 103, and that the above description is meant to be merelyillustrative, and not limiting, of the present invention. For example,another technology such as copper-to-copper bonding could be utilized tobond the distribution die 101 with the functional die 103. In thistechnology copper contacts on the distribution die 101 are aligned withrespective copper contacts on the functional die 103. These coppercontacts may be formed through a damascene process, and may also becapped with another metal such as tin or gold (although the cap is notnecessary). After the distribution die 101 and the functional die 103are properly aligned, the copper contacts are put under pressure andthen annealed to bond the copper contacts together, concurrently bondingthe two wafers.

FIGS. 6 a-6 c illustrate embodiments of the present invention in which asingle distribution die 101 is electrically connected to multiplestacked die. In each embodiment, the clock distribution network 105(FIG. 4) can be partitioned onto, for example, the distribution die 101,and the internal clock signal ICLK (FIG. 3) is distributed to aplurality of functional dies, such as a first functional die 103 and asecond functional die 601.

FIG. 6 a illustrates an embodiment in which the internal clock signalICLK can be distributed to multiple functional dies that are stackedvertically. In this embodiment the distribution die 101 is electricallyconnected to the first functional die 103 through a interface such asthe microbumps 505 as described above with reference to FIG. 5.Additionally, the internal clock signal ICLK may be also be distributedto the second functional die 601, for example, through the use ofthrough silicon vias 603 (TSV).

With TSV technology the internal clock signal ICLK is routed from thedistribution die 101 through the first pattern of contact pads 507, themicrobumps 505, and the second pattern of contact pads 509. However, oneor more of the second pattern of contact pads 509 are connected to vias603 that extend through the first functional die 103 to a third patternof contact pads 605 on an opposing side of the first functional die 103from the second pattern of contact pads 509. This third pattern ofcontact pads 605 are connected to a fourth pattern of contact pads 607on the second functional die 601 through any suitable type of connector,such as the microbumps 505 previously described above with reference toFIG. 5.

However, the distribution of the clock signal to a second functional die601 is not meant to be limited to TSV technology. The above descriptionis meant to be merely illustrative, and not limiting in any manner. Anysuitable connection technology for connecting multiple die is alsointended to be included within the scope of the present invention.

Furthermore, one skilled in the art will realize that the types ofbonding illustrated herein are merely examples and that any suitablebonding technology may be used to attach and electrically couple thedistribution die to one or more functional dies. For example, anysuitable type of electrical connections, such as die-to-die vias, arealso meant to be included within the scope of the present invention.

FIG. 6 b illustrates another configuration of connecting a singledistribution die 101 to a first functional die 103 and a secondfunctional die 601. In this configuration, the first functional die 103and the second functional die 601 are located next to each other. Thedistribution die 101 overlaps at least a portion of both the firstfunctional die 103 and the second functional die 601. The distributiondie 101 has a first pattern of contact pads 507 that can be connected tothe second pattern of contact pads 509 on the first functional die 103and can also be connected to the fourth set of contact pads 607 on thesecond functional die 601. This allows the internal clock distributionsignal ICLK to be distributed to both the first functional die 103 andthe second functional die 601.

FIG. 6 c illustrates yet another configuration for connecting a singledistribution die 101 to a first functional die 103 and a secondfunctional die 601. In this configuration, the distribution die 101, thefirst functional die 103, and the second functional die 601 are alllocated on and connected to a single substrate 609 that routes theinternal clock signal ICLK from the distribution die 101 to the firstfunctional die 103 and the second functional die 601. The distributiondie may be connected to the substrate 609 through the microbumptechnology described above with reference to FIG. 6 a, with themicrobumps 505 connecting the first pattern of contact pads 507 on thedistribution die 101 with a fifth pattern of contact pads 611 on thesubstrate 609. Metal lines within the substrate 609 transport theinternal clock signal ICLK to the first functional die 103 (through asixth pattern of contact pads 613 connected to the second pattern ofcontact pads 509 through a connection technology such as microbumps 505)and to the second functional die 601 (through a seventh pattern ofcontact pads 615 connected to the fourth pattern of contact pads 607through a connection technology such as microbumps 505).

FIGS. 7 a-7 b illustrate embodiments of the present invention in which asingle functional die 103 may be connected to a first distribution die101 as well as a second distribution die 701. FIG. 7 a illustrates anembodiment in which the single functional die 103 is connected to thesecond distribution die 701 through an appropriate technology such asmicrobumps 505 connecting the second pattern of contact pads 509 to aneighth pattern of contact pads 703 on the second distribution die 701.The first distribution die 101 is connected to the functional die 103through TSV technology through the second distribution die 701, asdescribed above in relation to FIG. 6 a. In this embodiment the internalclock signal ICLK may be routed through the first distribution die 101,through the first pattern of contact pads 507 and microbumps 505 to aninth set of contact pads 707 in the second distribution die 701. Theinternal clock signal ICLK is then routed through one or more vias 705to a tenth pattern of contact pads 703 on the second distribution die701 through microbumps 505, and finally to the second pattern of contactpads 509 on the first functional die 103.

FIG. 7 b illustrates another embodiment of the present invention inwhich a first distribution die 101 and a second distribution die 701 areconnected to a single functional die 103. In this embodiment the firstdistribution die 101 and the second distribution die 701 are locatedside-by-side. The first distribution die 101 may be connected to thefunctional die 103 through a bonding technology such as microbumps 505that connect the first pattern of contact pads 507 on the firstdistribution die 103 with the second pattern of contact pads 509 on thefunctional die 103. The second distribution die 701 may be connected tothe functional die 103 through a technology such as microbumps 505 thatconnect the tenth pattern of contact pads 703 to the second pattern ofcontact pads 509 on the functional die 103.

One of ordinary skill in the art will realize that the embodiments ofthe present invention that have been presented above with respect toFIGS. 5-7 are merely meant to be illustrative of embodiments of thepresent invention, and are not meant to limit the invention to theconfigurations or sizes described above. The present invention isintended to include dies of varying sizes and all of the configurationsused to connect distribution dies and functional dies, includingmultiple distribution dies connected to multiple functional dies. Theseconnections are intended to be made by any suitable connectiontechnology and any suitable architecture.

By designing and forming the clock distribution network 105 on aseparate distribution die 101, coupling between the clockingdistribution network 105, the power network, and the signal network isgreatly reduced. Further, by placing the clock distribution network 105on the distribution network die 101, the design constraints caused byhaving to route the distribution network 105 around the functionalcircuits 109 a-109 n and the power distribution network (not shown) arereduced. Accordingly, the distribution lines, or “branches,” can beeasily and purposely skewed in order to minimize the overall skew andcreate proper synchronization.

Advantageous features of embodiments of the present invention mayinclude a method of distributing a clock signal, the method comprisinggenerating a clock signal with a clock signal generator, and routing theclock signal to an input of a clock distribution network located on adistribution die. The clock signal is routed from the clock distributionnetwork to a first set of one or more functional circuits located on afirst functional die, the first functional die being different from thedistribution die.

The method could further include wherein the clock signal generator islocated on the distribution die and wherein the clock signal generatoris located on the first functional die. The clock signal is routed fromthe clock distribution network to the first set of functional circuitsthrough microbumps.

The method could further include routing the clock signal from the clockdistribution network to a second set of functional circuits located on asecond functional die and wherein the clock signal is routed from theclock distribution network to the second set of functional circuitsusing through silicon vias. The method further comprising routing theclock signal through a plurality of buffers electrically coupled to theclock distribution network.

Other advantageous features of embodiment of the present invention mayinclude a method for distributing a clock signal comprising supplying aclock signal to an input of a clock distribution network located on adistribution die. The clock distribution network comprises an input anda first set of one or more outputs, and routing the clock signal fromthe first set of one or more outputs to respective ones of a firstplurality of functional circuits located on a first functional die, thefirst functional die being different from the distribution die. Theclock signal generator is located on the distribution die and whereinthe clock signal generator is located on the first functional die. Theclock signal is routed from the first set of one or more outputs to thefirst plurality of functional circuits through microbumps.

The method could further comprise routing the clock signal from a secondset of one or more outputs of the clock distribution network torespective ones of a second plurality of functional circuits located ona second functional die, the second functional die being different fromthe distribution die and the first functional die. The clock signal isrouted from the second set of one or more outputs to respective ones ofa second plurality of functional circuits using through silicon vias.

The method of the clock distribution network further comprises aplurality of buffers.

Another feature of the embodiment of the present invention could includea method of supplying a clock signal, the method comprising generating afirst clock signal with a first clock signal generator and routing thefirst clock signal to a first distribution network located on a firstdistribution die. The first distribution network comprises a first inputand first outputs and generates a second clock signal with a secondclock signal generator. Then the second clock signal is routed to asecond distribution network located on a second distribution die, thesecond distribution network comprising a second input and second outputsand routes the first clock signal from the first outputs to firstfunctional circuits located on a first functional die. The firstfunctional die being different than the distribution die; and routes thesecond clock signal from the second outputs to second functionalcircuits located on a second functional die, the second functional diebeing different than the distribution die and the first functional die.

The method could further comprise routing the first clock signal fromthe first distribution die to third functional circuits located on oneor more additional functional dies, the one or more additionalfunctional dies being different from the first functional die or thesecond functional die. The clock signal generator is located on thedistribution die and on the first functional die. The clock signal isrouted from the first set of one or more outputs to respective ones ofthe first set of one or more functional circuits through microbumps, andwherein the clock signal is routed from the second set of one or moreoutputs to respective ones of a second plurality of functional circuitsusing through silicon vias.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. For example,there are multiple interface technologies that can be used to form theinterface between the distribution die 101 and the functional die 103.Any of these interfaces that achieve substantially the same result asthe corresponding embodiments described herein may be utilized accordingto the present invention.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, manufacture, compositions of matter, means, methods, or steps,presently existing or later to be developed, that perform substantiallythe same function or achieve substantially the same result as thecorresponding embodiments described herein may be utilized according tothe present invention. Accordingly, the appended claims are intended toinclude within their scope such processes, machines, manufacture,compositions of matter, means, methods, or steps.

1. A semiconductor device comprising: a first die comprising at leastone functional circuit, the first die having a plurality of contacts;and a first distribution die electrically coupled to the functionalcircuit, the first distribution die having a clock signal distributionnetwork formed therein, the clock signal distribution network routing afirst clock signal to one or more of the plurality of contacts.
 2. Thesemiconductor device of claim 1, wherein the first distribution diefurther comprises a clock signal generator formed therein andelectrically connected to the clock signal distribution network.
 3. Thesemiconductor device of claim 1, wherein the first die further comprisesa clock signal generator generating a second clock signal, the secondclock signal being electrically coupled to at least one of the pluralityof contacts, the first clock signal being based at least in part on thesecond clock signal.
 4. The semiconductor device of claim 1, wherein thefirst distribution die is electrically connected to the first die bymicrobumps.
 5. The semiconductor device of claim 1, wherein the firstdie and the first distribution die are electrically connected bycopper-to-copper bonding.
 6. The semiconductor device of claim 1,further comprising a one or more additional die, each additional diecomprising at least one functional circuit electrically coupled to theclock signal distribution network.
 7. The semiconductor device of claim6, wherein the second die is electrically coupled to the clock signaldistribution network using through silicon vias.
 8. The semiconductordevice of claim 1, further comprising one or more additionaldistribution dies, each additional distribution die having an additionalclock signal distribution network formed therein and electricallyconnected to the first die.
 9. A semiconductor device comprising: afirst die comprising a first plurality of integrated circuit contacts,the first plurality of integrated circuit contacts including a firstplurality of clock input contacts; a distribution die comprising a clocksignal distribution network, the clock signal distribution networkhaving a first plurality of clock output connections; and at least oneelectrical connection between respective ones of the first plurality ofclock input contacts and the first plurality of clock outputconnections.
 10. The semiconductor device of claim 9, wherein the atleast one electrical connection comprises microbumps.
 11. Thesemiconductor device of claim 9, wherein the distribution die furthercomprises a clock signal generator formed therein and electricallyconnected to the clock signal distribution network.
 12. Thesemiconductor device of claim 9, wherein the first die further comprisesa clock signal generator generating a second clock signal, the secondclock signal being electrically coupled to at least one of the pluralityof contacts, the first clock signal being based at least in part on thefirst clock signal.
 13. The semiconductor device of claim 9, furthercomprising: a second plurality of clock output connections on thedistribution die; a second die comprising a second plurality ofintegrated circuit contacts, the second plurality of integrated circuitcontacts including a second plurality of clock input contacts; and oneor more electrical connections between respective ones of the secondplurality of clock input contacts and the second plurality of clockoutput connections.
 14. The semiconductor device of claim 13 wherein theone or more electrical connections between respective ones of the secondplurality of clock input contacts and the second plurality of clockoutput connections are through silicon vias.
 15. The semiconductordevice of claim 9 wherein the clock distribution network furthercomprises a plurality of buffers located along the clock distributionnetwork.
 16. A semiconductor device comprising: a first die comprising afirst plurality of integrated circuit contacts, the first plurality ofintegrated circuit contacts including a first plurality of clock signalinput contacts; a second die comprising a second plurality of integratedcircuit contacts, the second plurality of integrated circuit contactsincluding a second plurality of clock signal input contacts; adistribution die comprising a clock signal distribution network, theclock signal distribution network comprising a first plurality of clockoutput contacts and a second plurality of clock output contacts; a firstplurality of electrical connections between the first plurality of clockoutput contacts and the first plurality of clock input contacts; and asecond plurality of electrical connections between the second pluralityof clock output contacts and the second plurality of clock inputcontacts.
 17. The semiconductor device of claim 16, wherein thedistribution die further comprises a clock signal generator formedtherein, the clock signal generating a first clock signal, the firstclock signal being electrically coupled to the first plurality of clockoutput contacts and the second plurality of clock output contacts. 18.The semiconductor device of claim 16, wherein the first plurality ofelectrical connections comprise microbumps.
 19. The semiconductor deviceof claim 16, wherein the second plurality of electrical connectionscomprise through silicon vias.
 20. The semiconductor device of claim 16,further comprising one or more additional distribution dies, eachadditional distribution die comprising a clock signal distributionnetwork and each additional distribution die being electricallyconnected to the first die, the second die, or both.